The present invention relates to irrigation systems of either the movable or fixed type. Conventional irrigation systems have a main supply line. In movable irrigation machines the supply line is commonly supported at intervals by wheels or mobile towers. Conventional movable or fixed irrigation systems have a main supply line which may be supported at some height above the earth, placed on the surface of the earth or buried within the earth. At various points along the supply line, a distribution tube extends from the main supply line to a pressure regulator and a nozzle or other suitable discharge devices. The distribution tube may extend upwardly, downwardly, laterally, or some combination of these. Conventional pressure regulators are well known in the art and supply a constant pressure to the associated discharge apparatus despite pressure fluctuations in the main supply line due to friction losses or undulating terrain. A typical regulator is shown in U.S. Pat. No. 4,543,985. Many different nozzles or other discharge apparatus are available to provide the desired application.
Current irrigation systems generally allow for the conveyance of a single fluid, usually water or, alternatively, water pre-mixed with chemicals or other additives. The fluid is supplied from a source into the main supply line and from there it flows into the distribution tubes. Conventional distribution tubes have a single fluid passageway for conveying the fluid. They do not provide for separate conveyances of fluid streams such as separate chemical or additive streams. If a mixed fluid stream is required, the chemicals or additives must be added to the water before it enters the main supply line or, alternatively, chemical or additive treatments must occur separately. Thus, there is a need to provide a distribution tube which allows for the incorporation of chemical or additive fluid streams therein.
In addition, current irrigation systems provide for only one fluid flow rate. Although some irrigation systems may allow for selected discharge apparatus to be turned on or off, they only provide for one rate of flow while the discharge apparatus is operating. There is no way to obtain an intermediate flow rate in instances where reduced flow rates are desired such as where the particular kind of crop has a low tolerance for overwatering. Thus, there is a need to provide a selectable flow control to each discharge apparatus thereby allowing for more than one rate of flow.
The present invention provides a distribution tube assembly which allows for multiple media streams. It further allows for selectable flow control, chemical application and the incorporation of additives into the irrigation water stream. It might further be utilized to carry granular media for distribution.